Tuesday, November 27, 2012

Risks and Problems associated with Solid Waste


Risks and problems associated with solid wastes; if solid wastes are not managed properly, there are many negative impacts that may result. Some of the most important are mentioned in the following list. The relative importance of each depends very much on local conditions. 
  • Uncollected wastes often end up in drains, causing blockages which result in flooding and insanitary conditions. 
  • Flies breed in some constituents of solid wastes, and flies are very effective vectors that spread disease. 
  • Mosquitoes breed in blocked drains and in rainwater that is retained in discarded cans, tyres and other objects. Mosquitoes spread disease, including malaria and dengue. 
  • Rats find shelter and food in waste dumps. Rats consume and spoil food, spread disease, damage electrical cables and other materials and inflict unpleasant bites.
  • Waste that is treated or disposed of in unsatisfactory ways can cause a severe aesthetic nuisance in terms of smell and appearance. 
  • Liquids and fumes, escaping from deposits of chemical wastes

Saturday, November 24, 2012

Waste Management Trends


Because Waste Treatment and Disposal are No Longer Enough

Reduce, Reuse, Recycle… These are the three R’s taught to us since we were in grade school.  In the University, we had also been taught of the four means of waste management—source reduction, recycling, treatment and disposal. We all know that source reduction points to efforts to decrease the amount of waste produced, that recycling is the process of transforming waste materials into reusable raw materials, that treatment is the process of removing or breaking down harmful chemicals from the water and air that comes out of a production plant, and that disposal is the release of waste materials back to the environment.
While waste management in the past had been focused more on disposal and treatment than on recycling and reduction, current trends show a reorientation of waste management efforts, emphasizing more on waste reduction than on treatment and disposal as shown in Figure 1.  Hence, while technologies developed in the past had been on emissions control such as catalytic converters in gasoline-operated cars, wastewater treatment technologies, and hazardous waste treatment technologies, current trends are more on the development of clean technologies such as new methods of combustion, production of different fine chemicals and the conversion of biomass for use as fuels.

courtesy by:
http://chedric.hubpages.com/hub/Clean-Technologies

Solid Waste Management


Solid waste management includes all activities that seek to minimize the health, environmental and aesthetic impacts of solid wastes. Solid waste can be defined as material that no longer has any value to the person who is responsible for it, and is not intended to be discharged through a pipe. It does not normally include human excreta. It is generated by domestic, commercial, industrial, healthcare, agricultural and mineral extraction activities and accumulates in streets and public places. The words "garbage", "trash", "refuse" and "rubbish" are used to refer to some forms of solid waste.
Very large quantities are produced by agriculture and mining, but these wastes will not be considered in this introduction. Wastes from houses, streets, shops, offices, industries and hospitals are usually the responsibility of municipal or other governmental authorities
Many people feel that solid waste management is a simple affair - simply putting waste into a vehicle and unloading it at a dump. If this were true, then why do so many towns suffer from uncollected refuse blocking streets and drains, harbouring flies and rats, and degrading urban environments? Successful solid waste management is rarely achieved without thought, effort and much learning from mistakes.
When most of us think of litter, we picture someone casually dropping a candy wrapper while strolling down the street. According to experts, there are seven major sources of litter: pedestrian, motorist, loading docks, improper household containment, improper commercial containment, construction and demolition sites, and uncovered trucks.

Risks and problems associated with solid wastes If solid wastes are not managed properly, there are many negative impacts that may result. The relative importance of each depends very much on local conditions. Uncollected wastes often end up in drains, causing blockages which result in flooding and insanitary conditions. Flies breed in some constituents of solid wastes, and flies are very effective vectors that spread disease. Mosquitoes breed in blocked drains and in rainwater that is retained in discarded cans, tyres and other objects. Mosquitoes spread disease, including malaria and dengue. Rats find shelter and food in waste dumps. Rats consume and spoil food, spread disease, damage electrical cables and other materials and inflict unpleasant bites. Waste that is treated or disposed of in unsatisfactory ways can cause a severe aesthetic nuisance in terms of smell and appearance. Liquids and fumes, escaping from deposits of chemical wastes.